Carburetor



Sept. 29, 1931. w. H. WEBER 1,324,852

CARIBURETOR v med May 11, 1927 s sheets-sheet 1 G H M C) Siggi/v4 I NVEN TOR.

A TTORNE Y.

Sept. 29, 1931. w.k H. WEBER' CARBURETGR Filed May l1, 1927 3Sheets-Sheet 2 FEVE- gt f I/" T 7/ .9X /07 my my y! 7M, l 7d mxI Il 1 Elgv fj 7? L :can f/ u l@ n Z da INVENTOR.

,427 l Y I B Y 4X2 i 77 ATTORNEY.

Sept. 29, 1931. w. H. WEBER 1,824,852.

' GARBURETOB 'Filed'may 11, 1927 s sheets-sheet 5 Patented Sept. 29,1931 uNITED STATES PATENT ori-"lola:4

WALTER H WEBER, F DETROIT, MICHIGAN, ASSIGNOR TO DETROIT LUBRICATOR COM-PAN'Y, oF DETROIT, MICHIGAN,

A CORPORATION 0F MICHIGAN CARBURETOR Application led May 11,

My invention relates broadly and generally to new and usefulimprovements in carburetors, and while not so limited, is articularlycapable of embodiment 'in car uretors of the so-called Stewart type.

One object of my invention is to provide an improved carburetor in whichproper supplies of fuel or fuel mixtures will be supplied duringdifferent periods or phases of operation of the engine, in order toproduce desired performance of the engine, 'particularly when the sameis employed to drive a motor vehicle.

The invention consists in the improved construction and combination ofparts, to be more fully described hereinafter, and the novelty of whichwill be particularly pointed out and distinctly claimed.

In the accompanying drawings l have fully and clearly illustrated apreferred embodiment of my invention, to be taken as a part of thisspecification, and wherein- Figure 1 is an elevation of my improvedcarburetor, the same being shown partly 1n section;

Fig. 2 is a plan view thereof;

Fig. 3 is a side View from the right of Fig. 1

Fig.4 is a side view, partly in section, and

from the left of Fig. 1;

Figs. 5, 6 and 7 are detail sectional views on line 5 5 of Fig. 4,showing operative positions of a priming valve;

Fig. 8 is a vertical detail section on line 8-8 of Fig. 4, and

Fig. 9 is a detail view of a hinge member.

vReferring to the drawings by characters of reference, 1 designates ahollow carburetor body, which is preferably, but not necessarily, formedof built-upV sections comprising a fuel reservoir 2, a fuel and airinlet element 3, and a mixing chamber 4. The carburetor body 1` may beformed from cast-or sheet-metal, or both, as desired.

The element 3 is separated from the mixing chamber 4 and the fuelreservoir 2 by spaced walls or partitions 5, 6, respectively, which,with t-he side wall 7, provides an air chamber 8. A. suitable conduit 9which is 50 fixed to the element 3 serves to admit air to 1927. serialNo. 190,483.

the chamber 8, and is provided with a flange 10 for connection, ifdesired, to air preheating means of any Well known type, such as, forexample, a sleeve surrounding the exhaust manifold (not shown) of theengine to be fed by the carburetor. The wall or partition 5 which iscup-shaped, having'a side wall 5, has an opening 11 therethrough for thepassage of air to the mixing chamber 4. The upper edge 12 ofopening 11forms a valve seat with which cooperates an air control valve 13 tobedescribed.

Coaxial with opening 11 and depending from the under side of wall 6, isa boss 14.- Which has an internally threaded bore 15. Threaded throughthe bore 15 is a guide sleeve 16, which extends into air chamber 8adjacent to opening 11, and has a shoulder 17 which abuts the boss 14. Anut 18 threaded on sleeve 16, or any other suitable means, may I0 beemployed-to lock the sleeve 16 rigidly in wall 6. Depending from thesleeve 16 and Apreferably integral therewith, is a dash-pot casing 19having an open lower end 20, and having a circumferential shoulder 21oppositely disposed with relation to shoulder 17. The casing 19 isexternally threaded be ond the shoulder 21, as at 22. Adjacent the seeve 16 and at the top of casing 19, there are a plurality of inletports 23 through which liquid fuel is supplied from the reservoir 2 tothe dash-pot casing. Fitted in the sleeve 16 and freely reciprocablelongitudinally thereof, is a valve stem 24, the upper end of whichprojects above sleeve 16 into air chamber 8, and the lower end of whichprojects below the said sleeve into the dash-pot casing or chamber 19.At its upper end 25 the stem 24 is fixed, as by threaded engagement, tothe valve 13. Threaded, or otherwise secured on the lower end of stem24, and within the dashpot chamber 19, is a piston 26 having a plurality of passages 27 therethrough which are provided with upwardlyopening check valves 28, preferably of the ball check type. The stem 24is hollow, having a bore 29 which is constricted, as at 30, to provide avalve port 31, and said bore having communication at its upper end 25with a fuel passage 32 in a nozzle plug 32u set in the valve stem 24,and 1f having a flaring upper end delivering into an outwardly flaringpassage 32b through the valve 13. Suitable air vent passages 33 leadfrom the air chamber 8 through the valve 13 and around the nozzle 32a tothe flaring opening 321. Depending from the valve 13 is an annularflange or skirt 34 which surrounds the sleeve 16.

The fuel reservoir 2, which is substantially cup-shaped, and preferablyof sheet-metal, has a base 35 having a central aperture 36 whichlpermitsthe base 35 to surround the threaded end 22 of casing 19 and abut theshoulder 21. When so positioned, the reservoir 2 will have its rim 37 inengagement with the underside of the air chamber 8. An internallythreaded cap 38 having threaded engagement with the end 22 of casing 19serves to hold the reservoir rim against the air chamber 8 and the base35 against the shouldeiI 21. A gasket 39 may be inserted between the cap38 and base 35 to seal the unlon, and

another gasket 39a is employed to seal the,

joint between rim 37 of reservoir 2 and the chamber 8.

The cap 38 has a neck 40 which is both internally and externallythreaded, and which is in the axi'al line of bore 29. Threaded into theneck 40 is a longitudinally adjustable supporting member 41 having amanual adjustment member, preferably 1n the form of a transverse rod orbar 42. At the inner or top end 43 of member 41, is fixed a valve 44,which may be in the form of a tapered needle or pin valve having a stem45 which projects through an opening 46 in the piston 26. The valve 44may be ad- 'justed relative to its port 31 by longitudinal movement ofthe screw support 41, to regulate flow of liquid fuel through the boreof the stem, the said fuel entering the bore through one or more ports44". Surrounding the support 41 and externally threaded on neck 40 is apacking nut 47 carrying packing 48 to seal the dash-pot chamber 19.

Within the reservoir 2 is an annular float 49, preferably of hollowsheet-metal construction, having a hinge member 50 fixed thereto. Thehinge member 50 has bearing eyelets 51 and an arcuate support 52.Carried by the side wall 7 is a cooperating hinge member 53 havingeyelets 54 and which is the counterpart of member 50. A pin 55 isjournaled in the eyelets 51, 54 to support the float 49 from wall 7 andto permit free movement of the float 49 in a vertical plane. Directlyabove the arcuate support 52, the side wall 7 of the air chamber 8 has avertical internal passage 56 which opens into the inner end of ahorizontal fuel supply inlet passage 57. Threaded into, or otherwisesecured in the vertical passage 56, is a hollow cylindrical valve guide58 having a valve seat 59, and vertically reciprocable in the guide 58is a flat sided valve stem 60 having an attaching ring or loop 61 at itslower. end through which is loosely passed the arcuate support 52. Atits upper end the valve stem 60 has a conical valve head 62 which isadapted to'engage the valve seat 59 to close the passages 56, 57. At theouter end of passage 57 the side wall 7 has an annular flange 63 whichsurrounds the passage 57. Threaded on the flange 63 is a cap 64 havingan internal shoulder 65, between which and the end of flange 63 isclamped a filter screen 66, preferably of fine wire mesh. The cap 64 hasa h ollow nipple 67 in the line of passage 57, which is externallythreaded for union with a fuel supply line (not shown), and throughwhich fuel is fed to the reservoir 2. In the Wall 7, preferably at apoint below the passage 57, is an air bleed or vent 66a leading from theatmosphere to the fuel reservoir 2 above the liquid level therein, andhaving its inner end registering with a port or aperture 67 through thehinge member 53.

Supported on the air inlet element 3 and sealed thereto by suitablegaskets 68, 69-and cap screws 70, is the mixing chamber and throttlebody member 4 having a flange 71 by which it may be attached to anengine intake manifold.` Adjacent the flange 71 is a threaded inletopening 71a for connection witha vacuum tank whereby the desiredsubatmospheric pressure may be maintained in such tank. In the saidmember 4 is a throttle valve 72, preferably of the butterfly type, whichis fixed by screw means 73 on a rotatable shaft 74 journaled in thesides of the chamber 4. One end 75 of shaft 74 extends through the wallof the chamber and carries an operating lever 76. A screw 78 threaded inlever 76 and kept in any fixed position by spring 77 determines theclosed or idling position of throttle valve 72, said screw 78 strikingagainst ange 71.

The wall 7 has a vertical boss 79 having a bore 80 extendinglongitudinally therethrough, said bore opening at its lower end into thefuel reservoir 2, and at its upper end to the atmosphere. Fitted withinthe bore 80 is a cylindrical tube or sleeve 81, the lower end of whichdips into the reservoir 2 below the normal fuel level, and whichterminates at its upper end substantially midway vof the height of thewall 52l of cup-shaped partition 5. The lower end of sleeve 81 has adisk member 82 fixed therein, as by threaded engagement, the disk memberhaving a central calibrated orifice 83 for the admission of liquid fuelto sleeve 81 from reservoir 2. Within the top of the sleeve 81 is a plug84 having a longitudinal axial bore 85 which at its lower end isenlarged and threaded, as at 86. The plug 84 has a pair of oppositelydisposed fiat sides 84 which space it at diametrically opposite pointsfrom the wall of the sleeve 81 to form air ducts 84", 84b opening intothe well sleeve 81', as is evident from Fig. 8. Transversely through theboss 79, the sleeve 81, the longitudinal axis of plug 84, and the wall5*?, is a passageway 87 having its outer end closed by a screw plug 88which projects through a side wall of sleeve 81 and into plug 84, andsupports said sleeve and plug in the bore 80. The inner end of thepassage 87 opens into the mixing chamber 4 (see Fig. 4). Above thepassageway 87, and preferably in the same vertical plane, is a secondpassageway 89, the inner end of which opens into the mixing chamber 4through the boss 79 and wall 5, said passage 89 being located above theupper end of the sleeve 81. The outer end of passageway 89 is sealed bya plug 90. Within the passageway 87 between the sleeve 81 and mixingchamber 4, is a plug 91 having a calibrated orifice 92. Depending fromthe plug 84 and within the sleeve 811, is a discharge tube 93, the upperend of which is threaded into the socket 86 in the'plug 84. The upperend of this tube 93 opens into the transverse passageway 87, while itslower end is open and terminates adjacent but above the disk member 82.Above the sleeve 81 and rotatably fitted in the bore 80, is a rotatablevalve 94, the underside of which clears the upper ends of sleeve 81 andplug 84 and the upper end of which projects upward above the boss 7 9.The underside of the valve 94 has a transverse, openended passage 95having an open lower side, one open end of which passage upon rotationof the valve 94, is adapted to communicate with the passageway orconduit 89. On the boss 79 is a lateral extension 96 through which is apassageway or air inlet 97, preferably in the same horizontal plane andat substantially rightangles to the passageway 89 and in a plane commonto that of the passageway 95. The valve 94 has a stem 98 to which isfixed an operating lever 99 which seats upon the upper face of boss 79and seals the valve 94 in the bore 80,and by which the valve may berotated, one side edge 100, of said lever 99, being provided, as shownin Fig. 2, with a-stop having abutments 101 and 102. Surrounding thestem 98 above the lever 99, is a coil spring 103, one end 104 of whichabuts'the carburetor body and the other end 105 of which is inengagement with the lever 99 to normally maintain the valve 94 in theposition shown in Fig. 4 with abutment 101 of the lever contacting afixed stop member 106. Overlying the coil spring 103 is one end of aleaf spring 107 having an aperture 107g by which it is passed onto thestem 98, the other end of spring 107 being fixed to the casing by ascrew 108, which also secures the stop-piece 106 to the carburetorcasing. This leaf spring holds the lever 99 on boss 79. Fixed on thecarburetor casing 1 is a bracket 109 which supports a tube (not shown)through which an operating wire (also not shown) leads from some pointwithin reach of the operator to the lever 99 for operation of the valve94.

The operation of the carburetor is as follows: The tapered needle or pinvalve 44 is preferably adjusted by the supporting member 41 so that port31 is slightly open when the air valve 13 is closed, so as to permitsuffcient liquid fuel to iow through the stem bore 29 and enter themixing chamber 4 to combine with air admitted through ports 33 and 11 toprovide a proper fuel mixture to allow the engine to run idle. As thethrottle 72 is opened, the engine having been running idle, thesubatmospheric pressure in the mixing chamber 4 will cause the valve 13to be lifted further depending on the degree of throttle opening, andcarry with it the stem 24, thus increasing the flow passage around thefuel valve 44. There is a slight clearance between the sides of thepiston and the wall of the dash-pot chamber 19, so -that the movement ofthe valve 13 is controlled. The ball checks 28 permit the piston to sinkand the valve 13 to close. The function of the dashpot and piston is toact as a vibrator dampener so that the air valve will not respond toevery minute fluctuation of vacuum, which might result in objectionablehammering of the valve 13 upon its seat 12. The action of the main airand fuel inlets is the same as is found in the well-known Stewart typeof carburetor, in which the air and fuel in the main mixture isproportioned to give maximum thermal efficiency, and need not be furtherdescribed.

On starting the engine, the lever 99 is moved manually clockwise of Fig.2 until the contact point 102 engages the stop 106. This will positionthe valve 94, as shown in Fig. 7, to close air inlet 97 and establishcommunication between tube 93 and discharge passage 89, so that solidliquid fuel alone will be drawn from the tube 93, where such fuel willdivide, part going through passage- Way 87 to the mixing chamber, andthe other part going through calibrated bore or port 85, passage 95, andconduit or passageway 89 to the mixing chamber 4. This is due to thefact that the valve 94 in position of Fig. 7, cuts oli' all aircommunication through air inlet 97 to the well, and opens the passageway89 to the well, and the resulting charge is, in effect, a primingcharge, as the solid fuel when mixed with'the air passing through themain mixing chamber supplies an overrich or sufficiently rich mixture tothe engine for starting. As soon as the engine is running, the valve 94is moved manually counterclock- Wise of Fig. 2 to the positionsubstantially as shown in Fig. 6, which cuts off the passageway 89 andpermits flow of solid liquid fuel in a relatively less quantity fromtube 93 to enter the mixing chamber 4, but only Ithrough the calibratedorifice92, the air inlet passage 97 still being closed by valve 94.

Afl-

As the engine warms up, the solid liquid fuel supplied from well 81,which is additional at all times to that supplied by the main fuelnozzle 32, might cause the mixture fed to the engine to be too rich. Toovercome this condition and cut down the amount of solid liquid fuel fedto the mixing chamber, the lever 99 is moved manually further in acountercloekwise direction, so that the valve 94 will be in someintermediate position to that shown in Figs. 5 and 6, and in thisposition the air passageway 97, 95 will be more or less open, admittingmore or less air to the well 81 and passage 89 will be maintainedclosed. The amount of liquid fuel drawn into -the mixing chamber 4through calibrated v orifice 92 will be in an inverse ratio to the 97,95 to calibrated orifice 85 is insufficient to satisfy the suctioncreated by the sub-atmospheric pressure in the mixing chamber 4, thenthe deficiency will be made up by liquid fuel drawn by the suction fromthe Well 81. Therefore, as the passage 97, 95 is opened bycounterclockwise movement of lever 99, the

amount of liquid fuel drawn from well 81 into the mixing chamber will bedecreased, due to admission of air through inlet passage 97. For normalrunning conditions the Valve 94 is returned by still further orcontinued counterc-lockwise movement until the abutment 101 engages thestop 106, when the valve 94 will be in the position shown in Figs. 2, 4,5 and 8, passage 89 being closed and passages 87 and 97 opened. In thislast position, air will enter through inlet passage 97 to passage 95,which is wide open, where it will divide, part passing through bore 85and passageway 87 to the mixing chamber, and part passing down throughthe spaces or ducts 84a, 84b between the sides of the plug 84 and sleeve81 into the latter. Due to the relative sizes of the passages 95, 97 andthe calibrated orifice 92, the passages 95, 97 bcing of greater capacitythan the orifice 92, the air pressure on the fuel in the well or sleeve81 will be substantially atmospheric at normal power demands or partthrottle, and no fuel will enter the mixing chamber 4 from the well 81,vthis effect resulting because the air entering through 97, 95 and 85 ismorel than sufficient to satisfy the suction through orifice 92. Underthe conditions just stated, the fuel is not drawn from the Well becausesubstantially atmospheric pressure is maintained in the horizontal boreof the plug 84, due to the fact that the air feed port 85 is larger thanthe calibrated orifice 92 in the passageway 87, and the suction in themixing chamber 4 exerted at the orifice 92 is not sufficient to withdrawair from the space over the well at a greater rate than the air issupplied to said space through the port 85. It will be understood. thatthe areas' of the port 85 and orifice 92 are so proportioned thatsubstantially atmospheric pressure will be maintained over the well,under the conditions just described, that is, during ordinary roadspeeds when the throttle is part open. When the throttle 72 is suddenlyopened, however, there will be, momentarily, a higher vacuum in themixing chamber 4 than at part throttle or normal running conditions,which higher vacuum will act to suck liquid fuel alone from the well 81to the extent of the quantity contained in the well into the mixingchamber to supply the necessary rich mixture for acceleration. Themomentarily higher vacuum mentioned causes li uid fuel to pass throughthe pas-v sage 87, cause the higher vacuum in the mixing chamberincreases the suction effect at the orifice 92 and exhausts air from thebore 85 at a greater rate than air is supplied to said bore through theorifice 85, re-

sulting in a sub-atmospheric pressure in the `bore 85a. At this timewhile there is Subatmospheric pressure in the bore 85a, the pressure ontop of the liquid in the well being atmospheric' because of the openducts 84", 84" leading to the air inlet 97, liquid fuel will beinstantly expelled from the tube 93 into said bore 85a, and thence passthrough the orifice 92 into the mixing chamber. The body of liquid fuelis drawn so suddenly from the Well 81 into the space over the well, andthence into the mixing chamber 4, that momentarily the air bleed 85ceases to function, or is sealed by the column of liquid fuel passingthrough the space over the well, port 92 and passage 97. If the higher;vacuum which accompanies wide open throttle or maximum power demands ismaintained in the mixing chamber, then a mixture or emulsion of fuelfrom well 81 and air which passes through ports 84, 84h, and down aroundtube 93 'entering the bottom of tube 93 with fuel from orifice 83, willbe fed to the mixing chamber through orifice 92, since the air enteringthrough passageway 95 and calibrated orifice 85 will be insufiicient'tosatisfy the demand at orifice 92, and the emulsion of air and fuelentering the bottom of tube 93, will be aspirated fronithe well 81 bythe air entering at 85, which mixture will be constant in quantity perunit of time.

By the invention shown and described, it will be seen that I haveprovided -efiicient means whereby upon starting, solid liquid fuel willbe admitted to the mixing chamber under such conditions that such fueladded to the main supply will afford a sufficiently rich mixture forstarting, even though the supply of liquid fuel from the main jet wouldproduce a mixture which would be relatively too lean. This result isunder manual control of the operator, so that it may be produced or not,as desired. During a warming up period after starting, the lever 99 ispermitted to move toward the position shown in Fig. 2, the valve 94first moving to the position shown in Fig. 6, during which supplementalliquid fuel passes only through calibrated orifice 92 to enrich thenormal flow through the carburetor. The valve 94 may pass quicklythrough this position or may be manually held at this position, ifdesired, until proper warming up of the engine is assured. During normalrunning, i. e., part throttle, the valve 94 is permitted to assume theposition shown in Figs. 2 and 5, under which condition no fuel will bedrawn from well 81. Should the throttle be opened wide for maximum powerduring normal running conditions, the increased suction through thecarburetor body will first draw a charge of solid liquid fuel from thetube 93, to momentarily enrich the mixture, and then upon continuedmaximum power demand the air drawn through passage 97 and over top oftube 93, will aspirate the fuel and deliver a supplemental mixturethereof through calibrated orifice 92 into the mixing chamber.

By the expression solid fuel` as used herein, is meant liquid fuel whichis not in the form of an emulsion with air,l or a mixture of fuel andair.

What I claim and desire to secure by Letters Patent of the United Statesis:

i. In a carburetor, a casing having a mixing chamber, main air and fuelinlets adapted to discharge into said mixing chamber, supplementary fueland air supply means adapted to discharge into said mixing chamber, saidfuel supply means comprising a well, a tube depending into said well andhaving communication with said chamber and said air supply means, saidair supply7 means having communication with said well around said tubeto admit air to the lower end of said tube, and a valve controllingcommunication with said well around said tube and controlling saidsupplementary fuel and air supply means, said valve having means whichin one position of said valve will permit admission of solid liquid fuelthrough said supplementarv means to said mixing chamber and which inanother position will permit admission of fuel and air through saidsupplementary means to said mixing chamber.

. 2. In a carburetor, a casing having a mixing chamber, main air andfuel inlets to said mixing chamber, a passageway opening into saidmixing chamber, a fuel well, a tube depending into said well and openinginto said passageway, means to supply air to said passageway and to saidwell around said tube to admit-air to the lower end of said tube, and avalve to control said air supply means and thereby regulate supply ofair to said passageway and the space in said well fuel, or fuel and air,may be admitted through said passageway to said mixing chamber.

3. In a carburetor, a casing having a mixing chamber, main air and fuelinlets to said mixing chamber, a plurality of passageways leading tosaid mixing chamber independent- .ly of said main air and fuel inlets,means to supply fuel to said passageways, means to supply air to certainof said passageways, and a valve having means to cut off said air supplymeans, said valve having means to open one of said passageways when saidvalve means cuts off said air supply means.

4. In a carburetor, a casing, main fuel and air inlets to said casing, afuel well,passage ways from said fuel Well int-o said casing and subjectto suction effect of sub-atmospheric'pressure in said mixing chamber,certain of said passageways being calibrated and other of saidpassageways being unrestricted, an air inlet port, and valve meansoperable to establish communication between said air port, said well andsaid certain calibrated air inlets to said casing, a fuel reservoir, a

well having a calibrated inlet port communieating with said reservoir,outlet passageways from said well into said casing and subject tosuction effect of sub-atmospheric pressure in said mixing chamber, oneofwhich passageways is calibrated, an air inlet port, and a valve deviceadapted to connect said air inlet port with said well and saidcalibrated passageway, and simultaneously cut off communication betweenanother of said passageways and said well. V

6. In a carburetor, a casing, main fuel and air inlets to said casing, afuel reservoir supplying fuel to said main fuel inlet, a well having acalibrated inlet port communicating with said reservoir, outletpassageways from said well into said casing and independent of said maininlets, one kof which outlet passageways is calibrated and another ofwhich is uncalibrated, an air inlet port, a valve device including meansto close said air inlet port and open communication between saiduncalibrated passageway and said well, said valve device being adaptedto connect said air inlet port with said well and said calibratedpassageway.

7. A carburetor comprising a mixing chamber, main air and fuel inlets tosaid mixing chamber, a fuel well, passageways leading from said fuelwell into the mixing chamber independently of said main air and fuelinlets, an air inlet adapted to communicate with said well, and valvemeans acting when in one position to close said second air inlet andestablish communication between one of said passageways and said well,and acting when in another position to cut off communication between oneof said passageways and the well and open communication between thesecond air inlet and the well whereby fuel from the well may bedischarged through another passageway into the mixing chamber.

8. A carburetor comprising a mixing chamber, main air and fuel inlets tosaid mixing chamber, a fuel well, passageways leading from said fuelwell into the mixing chamber independently of said main air and fuelinlets, an air inlet adapted to communicate with said well, and valvemeans acting when in one position to close said second air inlet andestablish communication between one of said passageways and said well,and acting when in another position to cut off communication betweensaid one passageway and the well and open communication between saidsecond air inlet and the well whereby fuel from the well may be'discharged through another of said passageways intothe mixing chamber,said valve means having an intermediate position whereby said second airinlet and one passageway are closed.

9. A carburetor comprising a mixing chamber, main air and fuel inlets tosaid mixing chamber, a fuel well, passageways leading from said fuelwell into the mixing chamber independently of said main air and fuelinlets, one of said passageways being restricted, an air inlet adaptedto communicate with said well, and valve means acting when in oneposition to close said second air inlet and establish communicationthrough another of said passageways with said well, and acting wheny inanother position to cut off communication between said other passagewayand the well and open communication between said second air inlet andthe well, whereby fuel from the well may be discharged through therestricted passageway into the mixing chamber.

10. A carburetor comprising a mixing chamber, main air and fuel inletsto said mixing chamber, a fuel well, passageways leading from' said fuelWell into the mixing chamber independently of said main air and fuelinlets, one of said passageways being restricted, an air inlet adaptedto communicate with said Well, and valve means acting when in oneposition to close said second air inlet and establish communicationthrough another of said passageways with said well, and

` acting when in another position to cut ofi' communication between saidother passageway and the well and open communication between said secondair inlet and the well, whereby fuel from the Well may be dischargedthrough the restricted passageway into the mixing chamber, vsaid valvemeans having an intermediate position whereby said second air inlet andsaid other passageway are closed.

11. A carburetor comprising a mixing chamber, main air and fuel inletsto said mixing chamber, a fuel well, passageways leading from said fuelwell into the mixing chamber independently of said main air and fuelinlets, one of said passageways being in constantcommunication with thefuel well, an air inlet adapted to communicate with said well, and valvemeans acting when in one position to close said second air inlet andestablish communication through another of said passageways with saidwell, and acting when in another position to cut ofi' communicationbetween said other passageway and the well and open communicationbetween said second air inlet and the well whereby fuel from the lwellmay be discharged through said constantly open passage into the mixingchamber.

12. A carburetor comprising a mixing chamber, main air and fuel inletsto said mixing chamber, a fuel Well, al passageway leading from saidfuel well into said mixing chamber, said passageway being independent ofsaid main air and fuel inlets, a calibration in said passageway andforming a chamber between said calibration and the communication betweenthe passageway and said well, means to supply air to said secondchamber, and a valve to control the supply of air to said second chamberto infiuence fuel How from said well whereby solid liquid fuel, or fueland air, may be admitted through said passageway to said mixing chamberto modify the mixture supplied by said main fuel and air inlets.

13. In a carburetor, a casing having a mixing chamber, main air and fuelinlets to said mixing chamber, a fuel well, means to admit liquid fuelto said well, a discharge passageway from said well to said mixingchamber and subject to the suction effect of sub-atmospheric pressure insaid mixing chamber, an air inlet leading to said well, and a valveoperable to one posit-ion to close said discharge passageway and opensaid second air inlet, and operable to another position to close saidsecond air inlet and said discharge passageway, and a second dischargepassage leading from said well to said mixing chamber and acting todischarge fuel from said well when said first-named passageway isclosed.

14. In a carburetor, a casing having a mixing chamber, main air and fuelinlets to said mixing chamber. a fuel well, means to admit liquid fuelto said well, a discharge passageway from said well to said mixingchamber, a second discharge passageway from said well to said mixingchamber, both of said passageways opening into said chamber above saidm'ain inlets and being open to suction effect of sub-atmosphericpressure in said mixing chamber, an air inlet to said second passagewayand said well, and a valve to control said second air inlet and controldisido ies

4charge of fuel from said well through said passageways to the mixingchamber.

15. In a carburetor, a casing having a mixing chamber, main air and fuelinlets to said mixing chamber, a fuel well, means to admit liquid fuelto said well, a discharge passageway from said well to said mixingchamber, a second discharge passageway from said well to said mixingchamber, an air inlet leading to said well, and a valve to control saidsecond air inlet and one of said passageways and operable to cut off theair supply through said second air inlet and subject both saidpassageways and said well to the suction of the mixing chamber wherebyliquid fuel will be drawn from the well through both said passagewaysinto the lnixing chamber.

16. In a carburetor, a casing having a mixing chamber, main air and fuelinlets to said chamber, a plurality of passageways independent of saidmain inlets and opening into said mixing chamber, said passageways beingopen to suction effect of sub-atmospheric pressure in said mixingchamber, means to supply liquid fuel to said passageways, means tosupply air to certain of said passageways and said fuel supply means,and a valve dcvice including provisions serving when said valve deviceis in one position to open one of said passageways to establishcommunication between said liquid fuel supply means and the mixingchamber, and to cut off air supply through said means to supply air tosaid passageways and said fuel supply means, and when said valve deviceis in another position to close communication between one of saidpassageways and said liquid fuel supply means and admit air from saidmeans to supply air to another of said passageways and said liquid fuelsupply means.

17. A carburetor comprising a mixing chamber having a throttlecontrolled'outlet,

'main air and fuel inlets to said chamber.

valve means controlling said inlets. the position of said means beingdetermined by the sub-atmospheric pressure in said chamber, the pressuredecreasing as the throttle is moved toward full open position, arestricted passageway leading into said chamber and subject to thesuction effect in the mixing chamber, a fuel well communicating withsaid passageway, an air inlet to said passageway and the well to placethe well under substantially atmospheric pressure, said passageway andthe opening from said air inlet to said passageway being so proportionedthat the pressure in said chamber attending part open throttle will beineffective to draw fuel from said well but lower sub-atmosphericpressure attending wider open throttle will draw a mixture of fuel andair from said passageway, a second passageway from said well to saidchamber, and means controlling said second passageway and said secondair inlet and operable to open said second passageway and close saidsecond air inlet whereby a charge of liquid fuel will be'drawn from saidwell through both said passageways into said chamber, said means beingalso operable to close said second air inlet and said second passagewaywhereby liquid fuel will be drawn through said restricted passagewayinto said chamber, and said means being also operable to close saidsecond passageway and open said second air inlet whereby air and fuelwill be drawn through said restricted passageway at lowersub-atmospheric pressure in said chamber.

18. A carburetor comprising a mixing chamber having a throttlecontrolled outlet, main air and fuel inlets to said chamber, valve meanscontrolling said inlets, the position of said means being determined bythe sub-atmospheric pressure in said chamber, the pressure decreasing asthe throttleis moved toward full open position, a restricted passagewayleading into said chamber and subject to the suctionfect in the mixingchamber, a fuel well communicating with said passageway, an air inlet tosaid passageway andv the well tc place the well under substantiallyatmospheric pressure, said passageway and the opening from said airinlet to said passageway being so proportioned that the pressure in saidchamber attending part open throttle will be ineffective to draw fuelfrom said well but lower sub-atmospheric pressure attending wider openthrottle will draw a mixture of fuel and air from said passageway, asecond passageway from said well to said chamber, and means controllingsaid second passageway and said second air inlet and operable to opensaid second passageway and close said second air inlet whereby a chargeof liquid fuel will be drawn from said well through both saidpassageways into said chamber, said means being also operable to closesaid second air inlet and said second passageway whereby liquid fuelwill be drawn through said restricted passageway into said chamber, andsaidmeans being also operable to close said second passageway and opensaid second air inlet whereby at sudden lower sub-atmospheric pressurein said chamber liquid fuel will be drawn from said well through saidrestricted passageway and upon maintenance of lower sub-atmosphericpressure in said chamber air and fuel will be drawn through saidrestricted passageway.

In testimony whereof I have hereunto subi scribed my name.

WALTER H. WEBER.

